Exercise Helps Prevent Breast Cancer

Exercise may help prevent breast cancer, and help those whodo get it cope, two new studies show.

The first study, based on interviews with 15,000 women, shows that women whoget more than six hours of strenuous exercise a week, and have no familyhistory of breast cancer, may be 23% less likely to develop the disease thanwomen who don't exercise at all.

The second study shows a 12-week group exercise program may boost mood andphysical function in women with early-stage breast cancer.

The researchers don't promise exercise will prevent breast cancer, or blamebreast cancer on a lack of exercise. Many factors affect cancer risk.

But, they do report exercise appeared to have benefits in protecting againstcancer for women of all ages.

"We have found that exercise likely offers protection against breastcancer regardless of a woman's stage in life," researcher Brian Sprague, ofthe University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, saysin an American Association for Cancer Research (AACR) news release.

"The take-home message for women should be that it is never too late tobegin exercising," Sprague says.

For the study, the researchers interviewed more than 15,000 women inMassachusetts, New Hampshire, and Wisconsin by telephone.

Those interviewed included 6,391 breast cancer patients and 7,630 womenwithout breast cancer. The women were 20-69 years old, roughly split betweenwomen 49 and under, those in their 50s, and those in their 60s.

Family History of Breast Cancer

Most had no family history of breast cancer, including the women with breastcancer themselves. While family history increases breast cancer risk, mostpatients don't have a family history of the disease.

During the 40-minute phone interview, the women noted whether they hadparticipated in the following activities at some point in their lives since age14: jogging/running, bicycling, calisthenics/aerobics/dance, racquet sports,swimming, walking/hiking for exercise, or other strenuous individual or teamactivities.

Most women, whether or not they had breast cancer, reported getting up tothree hours of weekly strenuous exercise at some point since age 14.

But 461 women without breast cancer, and 332 with breast cancer, said theyhad exercised strenuously for more than six hours weekly at some point sinceage 14 -- typically when they were in their teens and early 20s.

23% Less Likely

The women who reported getting more than six weekly hours of strenuousrecreational physical activity were 23% less likely to have breast cancer,compared to sedentary women, the study shows.

Exercise appeared to benefit women, regardless of age.

But the benefits were only seen in those with no family history of breastcancer.

The results held after adjusting for other breast cancer risk factors.

The study doesn't prove that exercise single-handedly prevented breastcancer or show how exercise may lower breast cancer risk.

The effects of exercise on hormones and weight may help, the researcherssuggest.

They note that they don't know if the women accurately recalled theirworkout habits.

Exercise for Breast Cancer Patients

The second study comes from researchers including Nanette Mutrie, PhD,professor of exercise and sport psychology at the University of Strathclyde inGlasgow, Scotland.

They studied 203 women with early-stage breast cancer who were 51 years old,on average, and hadn't been exercising.

First, the women completed surveys about their mood and quality of life.They also took a 12-minute walking test and had their shoulder mobilitychecked.

Next, Mutrie's team split the women into two groups.

One group participated in a 12-week group exercise program. The other groupwasn't asked to exercise.

Group Exercise Program

The women in the exercise group met twice weekly for 45-minute exerciseclasses. They were also encouraged to work out once a week on their own athome.

For the first six weeks of their 12-week program, the exercise groupgathered after classes to discuss topics such as setting goals and the healthbenefits of exercise.

Both groups of women repeated the psychological and physical tests at theend of the 12-week program and again six months later.

Those in the exercise group had improved their scores on the physical testsand also reported being in a better mood and coping better with breast cancer.Those benefits generally held at the six-month follow-up.B

It's not clear how much of the benefits were due to the workouts or to thesocial aspect of group exercise.

However, the researchers say doctors "should encourage activity forpatients with cancer," and that future studies should also investigatehome-based exercise programs, which may be more convenient for somepatients.